| The construction of asphalt pavement consumes a lot of resources such as asphalt and stone,and causes serious harm to the natural environment.At the same time,the rapid development of economy and the improvement of people’s consumption level have produced a large amount of waste.Today,when the government implements the sustainable development strategy,it will be a more environmentally friendly recycling method to replace some natural stones in asphalt concrete with waste glass materials,one of the wastes.As the strength of waste glass material is small and it is a hydrophilic acid material,its adhesion to asphalt is poor.The addition of waste glass material instead of some stone materials into asphalt concrete will have a great impact on the strength and durability of asphalt concrete.Generally,in the traditional thermoplastic asphalt mixture,the amount of waste glass aggregate should not be too much.Therefore,this paper prepared a high-performance polyurethane modified asphalt as binder,and studied the performance of polyurethane modified asphalt mixture mixed with waste glass aggregate,so as to realize the practical application of waste glass aggregate in polyurethane modified asphalt pavement.Firstly,through orthogonal test and selecting the three indexes of asphalt and viscosity index as the research object,the preparation process and content of polyurethane modified asphalt are studied,and three optimal combination schemes for preparing polyurethane modified asphalt are preliminarily obtained.Then,the modification mechanism and microstructure of polyurethane modified asphalt were analyzed by Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM).The results showed that there was a chemical reaction between polyurethane and asphalt.With the same amount of polyurethane and the shear time in a certain range,the polyurethane modifier has good compatibility with asphalt,and can form a dense structure.Then,the modification mechanism and microstructure of polyurethane modified asphalt were analyzed by Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM).The results show that there are new characteristic peaks in the infrared spectrum of polyurethane modified asphalt,that is,new functional groups are produced,and polyurethane reacts with asphalt.With the same amount of polyurethane and the shear time in a certain range,the polyurethane modifier has good compatibility with asphalt,and can form a dense structure.Finally,the mix proportion design and road performance of polyurethane modified asphalt mixture with 0%,5%,10%,15%and 20%waste glass aggregate were studied.The results show that the addition of waste glass aggregate to polyurethane modified asphalt mixture will have a certain impact on the high-temperature performance,low-temperature performance,water stability and skid resistance of the mixture.Using silane coupling agent and hydrated lime as anti stripping agent can greatly improve the water stability of the mixture.When the glass content is less than 15%,all indexes can meet the specification requirements. |
